1. Field of the Invention
This invention relates to an apparatus for adjusting the water level of a lock arranged in a canal.
2. Related Art Statement
In a canal connecting two water zones having a level difference to each other, a lock comprising plural lock gates is arranged over a full length of the canal and a vessel is placed in a lock room between the lock gates. Then, the lock gate is opened between the adjoining lock rooms, whereby water flows from a high water-level side into a low water-level side to adjust the water level between the lock rooms to thereby move the vessel therebetween.
In this conventional system, there are the following drawbacks:
(i) Since water always flows between the lock rooms from high water-level side to low water-level side, the water level at the high water-level side should be maintained at an adequate value and consequently the adjustment of the water level takes a too long time; and (ii) When the level difference in a large-scale canal is large, it is required to use a large amount of water in the locking operation. Therefore, if the high level water zone is lakes and marshes, there is a fear of drying up the water.